Freya has long been popular in the U.K. but has only taken off in the US in the last decade, along with the entire category of mythological names. Derived from the Old Norse name Freyja, meaning "Lady, noble woman", Freya is the name of the Norse goddess of love, beauty, and fertility.

Seraphina is one of the most-searched name on Nameberry, destined for even greater popularity. The highest-ranking angels, the six-winged seraphim, inspired the lovely name Seraphina.

Adeline has a lovely, old-fashioned "Sweet Adeline" charm, but has become so popular in the US under so many spellings and variations — with Adalynn and Adalyn also popular — that considered together it is far more popular than it first seems. Adorable nickname Addie is also pervasive.

Despite a return to such feminizations of male names as Josephine, Clementine, and Theodora, starchy Henrietta has not made it into that group. Still, if you look hard enough, you'll see that Henrietta has the same vintage charm.

Claudia is a classic name with ancient Roman roots. Never truly in or truly out, Claudia feels like a strong, modern choice that hits the sweet spot between too popular and too unusual..

Alexa was a steadily popular modern classic until Amazon's virtual assistant Alexa was released in 2013. It remains relatively well used in the US despite this, though its standing keeps dropping for obvious reasons. Too bad, because it's a strong and pretty name (which is probably why Amazon used it.)

This diminutive, similar to Alex or Alexis, has been yo-yoing in popularity since the turn of the 21st century.

Audrina is a name that owes its fame to overnight reality TV sensation Audrina Partridge, one of the original cast of the MTV reality series The Hills.